TECHNOLOGY & PATENTS:
Vibration Control by Confinement (VCC)
Energy Flow Control (EFC)
USA and International Patents
- 14 years of government and commercial projects
- 13 U.S. and international patents
- Expertise in noise/vibration/acoustics/shock analysis and control
- Capabilities in modeling simulation and analysis
- Capabilities in testing and evaluation
- Capabilites in field data collection and analysis
- Ability to secure government funds for R&D projects ($2.5 billion funding pool)
- Ability to secure sole source phase 3 awards
Publications
Abstract
Title: On the Sensor and Actuator Placement in Structures with Confined Vibrations
Author: Daryoush Allaei (QRDC, Inc.), Yin-Tsan Shih (QRDC. Inc.), and David Tarnowski (QRDC. Inc.)
Sensor and actuator optimization has been investigated by a number of researchers. For example, it is known that the placement of a sensor in the vicinity of a node can produce erroneous information about the contribution of the corresponding mode to the system response, while location of an actuator near a node point of a mode can result in an inability to control this mode (or at least the necessity of applying unrealistically large forces). It is now clear that it is essential to have an optimized sensor/actuator system in a "smart" structure in order to more efficiently and effectively analyze the condition of the structure and make the necessary adjustments. None of the previous studies have considered the case in which the vibration response is confined. If structural vibrations are confined to a section of the structure, nodal points of vibrations in unidirectional structures (i.e., rods and beam) and nodal lines in membrane- and shell-type structures (i.e., panels and cylinders) are converted to nodal lines and nodal surfaces, respectively, that can cause a significant degradation of the performance of sensors and actuators placed in the vicinity of such high stiffness regions. Therefore, modal confinement may be detrimental to the vibration control system. On the other hand, one may take advantage of the presence of the confined vibrations in a structure and optimize the sensor/actuator system by focusing on the areas where vibrations are confined. The purpose of this paper is twofold. (1) To report on a preliminary study [1,2] conducted to determine the effect of the confined vibrations on the sensor and actuator optimization (based on their number, type, location, and power requirement). (2) To introduce a preliminary design methodology to incorporate the confined modes in the design stage of the sensor/actuator system of smart structures. Based on our results, it is clear that modal confinement has a significant impact on the optimization of sensors and actuators. Our modified optimization procedure and design methodology have proven to be effective in addressing the related described issues.
Abstract
Title: On the Sensor and Actuator Placement in Structures with Confined Vibrations
Author: Daryoush Allaei (QRDC, Inc.), Yin-Tsan Shih (QRDC. Inc.), and David Tarnowski (QRDC. Inc.)
Sensor and actuator optimization has been investigated by a number of researchers. For example, it is known that the placement of a sensor in the vicinity of a node can produce erroneous information about the contribution of the corresponding mode to the system response, while location of an actuator near a node point of a mode can result in an inability to control this mode (or at least the necessity of applying unrealistically large forces). It is now clear that it is essential to have an optimized sensor/actuator system in a "smart" structure in order to more efficiently and effectively analyze the condition of the structure and make the necessary adjustments. None of the previous studies have considered the case in which the vibration response is confined. If structural vibrations are confined to a section of the structure, nodal points of vibrations in unidirectional structures (i.e., rods and beam) and nodal lines in membrane- and shell-type structures (i.e., panels and cylinders) are converted to nodal lines and nodal surfaces, respectively, that can cause a significant degradation of the performance of sensors and actuators placed in the vicinity of such high stiffness regions. Therefore, modal confinement may be detrimental to the vibration control system. On the other hand, one may take advantage of the presence of the confined vibrations in a structure and optimize the sensor/actuator system by focusing on the areas where vibrations are confined. The purpose of this paper is twofold. (1) To report on a preliminary study [1,2] conducted to determine the effect of the confined vibrations on the sensor and actuator optimization (based on their number, type, location, and power requirement). (2) To introduce a preliminary design methodology to incorporate the confined modes in the design stage of the sensor/actuator system of smart structures. Based on our results, it is clear that modal confinement has a significant impact on the optimization of sensors and actuators. Our modified optimization procedure and design methodology have proven to be effective in addressing the related described issues.
125 Columbia Court, Suite 6, Chaska, MN 55318
phone 952.556.5205 | fax 952.556.5206
email arash@qrdc.com
phone 952.556.5205 | fax 952.556.5206
email arash@qrdc.com